Sources said Ramkrishna decided to leave with immediate effect despite requests by the NSE board to stay on for some more time for transition. In a release, NSE said its board of directors has accepted the resignation of Ramkrishna. The board of NSE has appointed J Ravichandran, Group President, to hold charge of the office of CEO with immediate effect. Ramkrishna has handled various operational and strategic aspects of NSE for many years during her roles as Deputy and Joint Managing Director.